A disposable diaper typically has a thin, flexible, stretchy, low density polyethylene back sheet film, an absorbent core on the inside of the backsheet film, and a porous top sheet overlying the core. Such a diaper is positioned at the crotch of the wearer, the two ends of the diaper extending, respectively toward the front and back. Adjacent edges of the diaper at each side are then either positioned adjacent to each other or overlapped, a strip of pressure-sensitive adhesive tape or mechanical fastener tape being adhered to the back sheet at the border adjacent each of the two edges, holding the diaper closed.
A desirable closure system which is used for disposable articles employs a mechanical fastener, comprising, for example, hook and loop fastening components. Mechanical fastening systems have the advantage that they may be repeatedly used for opening and refastening the disposable article. Closure systems which contain mechanical fasteners are described in U.S. Pat. Nos. 5,019,073 and 5,176,671 and in European patent applications 0324 578, 0 563 457 and 0 563 458. In practice, application of mechanical closures requires in-line lamination of all fastening and release components on the diaper manufacturing line. However, in-line lamination complicates the manufacturing process of the desired products, and sometimes causes problems for the manufacturers.
On the other hand, closure system fastening devices provided in roll form are generally adhesive tapes. Closure systems which contain adhesive closure tapes are described in U.S. Pat. No. 4,778,701 and in European patent application 0 324 578. Closure systems that comprise adhesive fastening tapes have the disadvantage that the adhesive may become contaminated with body fluids, powder and baby oil etc., and the adhesion of the tape may decrease. The closing or reclosing, respectively, of the diaper could become ineffective resulting in premature failure of the diaper.
Disposable articles, especially disposable diapers, must be made at high rates of speed in order to be manufactured economically. It is thus desirable for a manufacturer of diapers to mount a single roll of closure tape in the form of a prelaminate containing all necessary elements directly in the line of manufacture. The closure tape is applied to the diaper as a composite tape, with the width of the roll being substantially the same as the desired length of the diaper closure to be fabricated. The closure tape is servered at right angles to the edges of the composite tape roll at intervals corresponding to the width of the desired closure tape and adhered at an appropriate location along the border of one side of the diaper.
Such prelaminated composite rolls must dispense the closure tape in the form of a closure tab systematically and consistently so that it can reliably be employed in mechanised manufacturing systems, for example, in the manufacturing of diapers. To avoid problems in manufacturing, it is necessary that the roll of closure tape-be stable, i. e. that the roll can be unwound continuously and at a high speed so that a closure tab may be cut therefrom without telescoping of the roll. Closure tab rolls containing mechanical fastener components are not known, because of the different calipers of the layers forming the laminate backing, the roll obtained can be unstable and unsuitable for the in-line manufacturing process of disposable articles.